package com.sky.service.impl;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.sky.constant.MessageConstant;
import com.sky.constant.StatusConstant;
import com.sky.dto.DishDTO;
import com.sky.dto.DishPageQueryDTO;
import com.sky.entity.Dish;
import com.sky.entity.DishFlavor;
import com.sky.exception.DeletionNotAllowedException;
import com.sky.mapper.DishFlavorMapper;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealDishMapper;
import com.sky.result.PageResult;
import com.sky.service.DishService;
import com.sky.vo.DishVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

@Service
@Slf4j
public class DishServiceImpl implements DishService {

    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private DishFlavorMapper dishFlavorMapper;
    @Autowired
    private SetmealDishMapper setmealDishMapper;

    /**
     * 新增菜品和对应的口味
     * @param dishDTO
     */
    @Transactional//涉及2张表操作：菜品、口味，故需要统一事物管理。
    public void saveWithFlavor(DishDTO dishDTO) {

        Dish dish =new Dish();
        BeanUtils.copyProperties(dishDTO,dish);
        //进入Mapper层处理两个表的修改：

        //1.向菜品表插入一条数据

        dishMapper.insert(dish);

        //2.向口味表插入n条数

            //获取insert生成的主键值。
        Long dishId = dish.getId();
            //获取口味集合
        List<DishFlavor> flavors = dishDTO.getFlavors();

        //口味不一定添加，所以用if
        if (flavors!=null&&flavors.size()>0){
            //先遍历一遍再插入，减少IO时耗
            flavors.forEach(dishFlavor -> {//Lamda表达式
                    //将dishId赋予。
                dishFlavor.setDishId(dishId);
            });
            //向口味表插入n条数
            dishFlavorMapper.insertBatch(flavors);
        }
    }

    /**
     * 菜品分页查询
     * @param dishPageQueryDTO
     * @return
     */
    public PageResult pageQuery(DishPageQueryDTO dishPageQueryDTO) {
        PageHelper.startPage(dishPageQueryDTO.getPage(),dishPageQueryDTO.getPageSize());
        Page<DishVO> page=dishMapper.pageQuery(dishPageQueryDTO);
        return new PageResult(page.getTotal(),page.getResult());
    }

    /**
     * 菜品批量删除
     * @param ids
     * @return
     */
    @Transactional
    public void deleteBatch(List<Long> ids) {
        //判断是否菜品能够删除——是否存在起售商品？
        for (Long id : ids) {
            //获得起售状态
            Dish dish = dishMapper.getById(id);
                //若为起售状态，则抛异常。
            if(dish.getStatus()== StatusConstant.ENABLE){
                throw new  DeletionNotAllowedException(MessageConstant.DISH_ON_SALE);
            }
        }
        //判断是否菜品能够删除——是否关联？
        List<Long> setmealIds = setmealDishMapper.getSetmealIdsByDishIds(ids);
            //若关联了套餐，则不能删除
        if(setmealIds!=null &&setmealIds.size()>0){
            throw new DeletionNotAllowedException(MessageConstant.DISH_BE_RELATED_BY_SETMEAL);
        }
        //删除菜品数据。(批量)
        dishMapper.deleteByIds(ids);
        //删除口味数据。(批量)
        dishFlavorMapper.deleteByIds(ids);
    }

    /**
     * 根据id查询菜品及口味
     * @return
     */
    public DishVO getByIdWithFlavor(Long id) {
        //1.1根据id查询菜品数据

        Dish dish = dishMapper.getById(id);

        //1.2根据id查询口味数据

        List<DishFlavor> dishFlavors = dishMapper.getByDishId(id);

        //2.将查询到的数据包装到dishVO里面放回

        DishVO dishVO = new DishVO();
        BeanUtils.copyProperties(dish,dishVO);

        dishVO.setFlavors(dishFlavors);

        return dishVO;
    }

    /**
     * 修改菜品
     * @param dishDTO
     */
    public void updateWithFlacor(DishDTO dishDTO) {
        Dish dish =new Dish();
        BeanUtils.copyProperties(dishDTO,dish);

       //1.修改菜品信息
        dishMapper.update(dish);

       //2.修改口味：先删除再插入
       //2.1删除口味信息
        dishFlavorMapper.deleteByIds(Collections.singletonList(dishDTO.getId()));//使用批量方法，用单条插入单条
       //2.2插入口味信息
        List<DishFlavor> flavors = dishDTO.getFlavors();

        //口味不一定添加，所以用if
        if (flavors!=null&&flavors.size()>0){
            //先 遍历一遍dishFlavor的id 再插入到数据库，减少IO时耗
            flavors.forEach(dishFlavor -> {//Lamda表达式
                //将dishId赋予。
                dishFlavor.setDishId(dishDTO.getId());
            });
            //向口味表插入n条数
            dishFlavorMapper.insertBatch(flavors);
        }
    }

    /**
     * 根据分类id查找菜品
     * @param categoryId
     * @return
     */
    public List<Dish> list(Long categoryId) {

        Dish dish = Dish.builder()// TODO 懵 这里这个build构造器有什么用？？
                .categoryId(categoryId)
                .status(StatusConstant.ENABLE)//启用
                .build();
        return dishMapper.list(dish);
    }
    /**
     * 条件查询菜品和口味
     * @param dish
     * @return
     */
    public List<DishVO> listWithFlavor(Dish dish) {
        List<Dish> dishList = dishMapper.list(dish);

        List<DishVO> dishVOList = new ArrayList<>();

        for (Dish d : dishList) {
            DishVO dishVO = new DishVO();
            BeanUtils.copyProperties(d,dishVO);

            //根据菜品id查询对应的口味
            List<DishFlavor> flavors = dishFlavorMapper.getByDishId(d.getId());

            dishVO.setFlavors(flavors);
            dishVOList.add(dishVO);
        }

        return dishVOList;
    }
}
